钙调磷酸酶B蛋白(calcineurin B like protein,CBL)是一类植物特有的Ca^(2+)传感器,在植物生长发育和逆境胁迫响应中发挥重要作用。CBL由4个典型的用于Ca^(2+)结合的手性延伸因子(elongation factor hands,EF-hands)结构域构成,并且每个...钙调磷酸酶B蛋白(calcineurin B like protein,CBL)是一类植物特有的Ca^(2+)传感器,在植物生长发育和逆境胁迫响应中发挥重要作用。CBL由4个典型的用于Ca^(2+)结合的手性延伸因子(elongation factor hands,EF-hands)结构域构成,并且每个EF-hand含有12个相对保守氨基酸组成的α-螺旋-环-α-螺旋结构。CBL启动子区域的顺式调控作用元件(如W-box、MBS和G-BOX等)可与上游转录因子(transcription factors,TFs)结合,通过激活或抑制下游基因的表达,从而进行转录调控。CBL通过脱落酸(abscisic acid,ABA)、呼吸爆发氧化酶同源物(respiratory burst oxidases homolog,RBOH)以及活性氧(reactive oxygen species,ROS)等信号通路调控植物气孔运动,减少水分蒸发,以适应各种逆境胁迫。大量研究表明,当植物受到盐、干旱、极端温度、营养胁迫和病原菌等逆境胁迫时,CBL能够迅速感知细胞内瞬时Ca^(2+)信号变化,不仅与CBL互作蛋白激酶(CBL-interacting protein kinase,CIPK)互作磷酸化下游靶标蛋白实现Ca^(2+)信号传导,还与其他蛋白质(如高亲和力K^(+)转运蛋白5、蛋白S-酰化转移酶10和2C类蛋白磷酸酶等)互作,从而正向或负向调控植物的抗逆性。此外,CBL介导植物器官和组织生长发育,通过调节糖信号促进果实成熟。CBL也与开花时间基因(gigantea,GI)结合以影响植物的开花时间。论文综述了植物CBL的发现、结构、分类、调控机制、生物学功能及其调控逆境胁迫响应的作用机制,并对其未来研究方向进行了展望,以期为农作物抗逆性遗传改良和生物育种提供基因资源和理论依据。展开更多
Vascular diseases such as aneurysm,hemadostenosis,aortic dissection are the primary causes of people’s death around world.As a result,it is significant to improve our knowledge about them,which can help to treat the ...Vascular diseases such as aneurysm,hemadostenosis,aortic dissection are the primary causes of people’s death around world.As a result,it is significant to improve our knowledge about them,which can help to treat the disease.Measuring the hemodynamic factor like the blood pressure,the wall shear stress(WSS)and the oscillatory shear index(OSI)is,however,still beyond the capabilities of in-vivo measurement techniques.So the use of mathematical models and numerical simulations for the studies of the blood flow in arteries and,in general,of the cardiovascular system,both in physiological and pathological conditions,has received an increasing attention in the biomedical community during the last two decades.Indeed,such studies aims at enhancing the current knowledge of the physiology of the cardiovascular system,as well as providing reliable tools for the medical doctors to predict the natural course of pathologies and,possibly,the occurrence of cardiovascular accidents.The computational vascular fluid-structure interaction(FSI)methodology is a numerical simulation method which is used to explain the hemodynamic factors.The WSS on the luminal wall and the mechanical stress in the vascular wall are directly related to the location of the lesion,and the blood flow strongly interacts with the vascular wall motion.The arterial wall continually adapts to the charge of its mechanical environment(due to,for example,growth,atrophy,remodelling,repair,ageing,and disease)and consequently undergoes several irreversible processes.Primary acute mechanisms of vascularFSI numerical simulation seem to be associated with(1)the arterial histology and the patient-specific complex geometry,(2)the typical mechanical properties of the layer,(3)properties of the blood is assumed as Newtonian fluid or non-Newtonian fluid based on the scale ofthe diameter of a vessel,(4)residual stress in the zero-pressure configuration.The arterial system naturally function under permanent physiological loading conditions.Fung defined the residual stress and measured the opening angle which varies greatly along the aortic tree.Consequently,most of these systems never experience a stress-free state in their’service life’,so a stress and strain fields are present in any in vivo obtained patientspecific cardiovascular geometry.The residual stress always be ignored in FSI simulation or be assumed to equal zero,and the vivo patient-specific artery geometry is assumed as zero-pressure configuration.To define the in vivo stress state of artery,an inverse problem needs to be solved:the undeformed shape of a body or its stress state in its deformed state needs to be determined given the deformed configuration and the loads causing this deformation.The modular inverse elastostatics method is used to resolve the pressure-induced stress state for in vivo imaging based on cardiovascular modeling proposed by Peirlinck.Here,we build a living vessel FSI model based on 4 key factors.In order to get the universal simulation results,we focus on idealized geometries of the vessel that represent healthy(physiological)conditions of the cerebral vasculature.Blood can be assumed as the Newtonian fluid at this scale.The anisotropic hyperelastic constitutive law(Gasser-Holzapfel-Ogden)is used in zero-pressure configuration.Afterwards,we propose the material parameters for the different constitutive models and the computational configurations.We demonstrate the importance of introducing the residual stress into vascular blood flow modeling by performing a comparing zero-pressure configuration and no-resistance configuration.We get the conclusion that the zero-pressure status model has smaller displacement and larger stress distribution compared with no-resistance stress model.Hence,the methodology presented here will be particularly useful to study the mechanobiological processes in the healthy and diseased vascular wall.展开更多
The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the ti...The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the title compound belongs to triclinic, space group P1 with a=1.089 7(3) nm, b=1.050 33(4) nm, c=1.858 5(4) nm, α=96.822(4)°, β=94.477(4)°, γ=94.636(3)°, V=3.001 3(12) nm3, Z=4, Dc=1.679 Mg·m-3, μ(Mo Kα)=1.582 mm-1, S=1.005, F(000)=1 496, R1=0.040 7, wR2=0.076 3. In compound, the tin atom has a distorted tetrahedral coordination configuration. The molecules are packed in one-dimensional chain polymer through a weak interaction between the chlorine atoms from adjacent molecules, respectively. CCDC: 286106.展开更多
飞机制造业的业务过程是一个复杂的、动态的、数据量大的系统工程.如何建立简单完整的产品研制模型一直是业务过程优化(BPI,Business Process Improvement)中的难题.通过借鉴波音公司关于飞机构型管理和产品结构模块化的相关思想,强调...飞机制造业的业务过程是一个复杂的、动态的、数据量大的系统工程.如何建立简单完整的产品研制模型一直是业务过程优化(BPI,Business Process Improvement)中的难题.通过借鉴波音公司关于飞机构型管理和产品结构模块化的相关思想,强调构型管理技术在飞机研制的全生命周期过程中的重要性,明确构型项(CI,Configuration Item)准确的数学定义.依据构型管理简化产品的信息模型和Petri网(PN,Petri Net)描述、优化产品过程模型的特点,将Petri网理论与构型项结合起来保证全生命周期过程中飞机研制模型的一致性和完整性.提出CI-PN模型来描述整个飞机研制的信息和过程模型,并给出对翼盒研制过程模型描述、分析和优化的实例.展开更多
文摘钙调磷酸酶B蛋白(calcineurin B like protein,CBL)是一类植物特有的Ca^(2+)传感器,在植物生长发育和逆境胁迫响应中发挥重要作用。CBL由4个典型的用于Ca^(2+)结合的手性延伸因子(elongation factor hands,EF-hands)结构域构成,并且每个EF-hand含有12个相对保守氨基酸组成的α-螺旋-环-α-螺旋结构。CBL启动子区域的顺式调控作用元件(如W-box、MBS和G-BOX等)可与上游转录因子(transcription factors,TFs)结合,通过激活或抑制下游基因的表达,从而进行转录调控。CBL通过脱落酸(abscisic acid,ABA)、呼吸爆发氧化酶同源物(respiratory burst oxidases homolog,RBOH)以及活性氧(reactive oxygen species,ROS)等信号通路调控植物气孔运动,减少水分蒸发,以适应各种逆境胁迫。大量研究表明,当植物受到盐、干旱、极端温度、营养胁迫和病原菌等逆境胁迫时,CBL能够迅速感知细胞内瞬时Ca^(2+)信号变化,不仅与CBL互作蛋白激酶(CBL-interacting protein kinase,CIPK)互作磷酸化下游靶标蛋白实现Ca^(2+)信号传导,还与其他蛋白质(如高亲和力K^(+)转运蛋白5、蛋白S-酰化转移酶10和2C类蛋白磷酸酶等)互作,从而正向或负向调控植物的抗逆性。此外,CBL介导植物器官和组织生长发育,通过调节糖信号促进果实成熟。CBL也与开花时间基因(gigantea,GI)结合以影响植物的开花时间。论文综述了植物CBL的发现、结构、分类、调控机制、生物学功能及其调控逆境胁迫响应的作用机制,并对其未来研究方向进行了展望,以期为农作物抗逆性遗传改良和生物育种提供基因资源和理论依据。
基金supported by the National Natural Science Foundation of China ( 11732001)
文摘Vascular diseases such as aneurysm,hemadostenosis,aortic dissection are the primary causes of people’s death around world.As a result,it is significant to improve our knowledge about them,which can help to treat the disease.Measuring the hemodynamic factor like the blood pressure,the wall shear stress(WSS)and the oscillatory shear index(OSI)is,however,still beyond the capabilities of in-vivo measurement techniques.So the use of mathematical models and numerical simulations for the studies of the blood flow in arteries and,in general,of the cardiovascular system,both in physiological and pathological conditions,has received an increasing attention in the biomedical community during the last two decades.Indeed,such studies aims at enhancing the current knowledge of the physiology of the cardiovascular system,as well as providing reliable tools for the medical doctors to predict the natural course of pathologies and,possibly,the occurrence of cardiovascular accidents.The computational vascular fluid-structure interaction(FSI)methodology is a numerical simulation method which is used to explain the hemodynamic factors.The WSS on the luminal wall and the mechanical stress in the vascular wall are directly related to the location of the lesion,and the blood flow strongly interacts with the vascular wall motion.The arterial wall continually adapts to the charge of its mechanical environment(due to,for example,growth,atrophy,remodelling,repair,ageing,and disease)and consequently undergoes several irreversible processes.Primary acute mechanisms of vascularFSI numerical simulation seem to be associated with(1)the arterial histology and the patient-specific complex geometry,(2)the typical mechanical properties of the layer,(3)properties of the blood is assumed as Newtonian fluid or non-Newtonian fluid based on the scale ofthe diameter of a vessel,(4)residual stress in the zero-pressure configuration.The arterial system naturally function under permanent physiological loading conditions.Fung defined the residual stress and measured the opening angle which varies greatly along the aortic tree.Consequently,most of these systems never experience a stress-free state in their’service life’,so a stress and strain fields are present in any in vivo obtained patientspecific cardiovascular geometry.The residual stress always be ignored in FSI simulation or be assumed to equal zero,and the vivo patient-specific artery geometry is assumed as zero-pressure configuration.To define the in vivo stress state of artery,an inverse problem needs to be solved:the undeformed shape of a body or its stress state in its deformed state needs to be determined given the deformed configuration and the loads causing this deformation.The modular inverse elastostatics method is used to resolve the pressure-induced stress state for in vivo imaging based on cardiovascular modeling proposed by Peirlinck.Here,we build a living vessel FSI model based on 4 key factors.In order to get the universal simulation results,we focus on idealized geometries of the vessel that represent healthy(physiological)conditions of the cerebral vasculature.Blood can be assumed as the Newtonian fluid at this scale.The anisotropic hyperelastic constitutive law(Gasser-Holzapfel-Ogden)is used in zero-pressure configuration.Afterwards,we propose the material parameters for the different constitutive models and the computational configurations.We demonstrate the importance of introducing the residual stress into vascular blood flow modeling by performing a comparing zero-pressure configuration and no-resistance configuration.We get the conclusion that the zero-pressure status model has smaller displacement and larger stress distribution compared with no-resistance stress model.Hence,the methodology presented here will be particularly useful to study the mechanobiological processes in the healthy and diseased vascular wall.
文摘The tetra(2, 4-dichlorobenzyl)tin was synthesized and characterized by elementary analysis, IR and 1H NMR. The crystal and molecular structure were determined by X-ray single crystal diffraction. The crystal of the title compound belongs to triclinic, space group P1 with a=1.089 7(3) nm, b=1.050 33(4) nm, c=1.858 5(4) nm, α=96.822(4)°, β=94.477(4)°, γ=94.636(3)°, V=3.001 3(12) nm3, Z=4, Dc=1.679 Mg·m-3, μ(Mo Kα)=1.582 mm-1, S=1.005, F(000)=1 496, R1=0.040 7, wR2=0.076 3. In compound, the tin atom has a distorted tetrahedral coordination configuration. The molecules are packed in one-dimensional chain polymer through a weak interaction between the chlorine atoms from adjacent molecules, respectively. CCDC: 286106.
文摘飞机制造业的业务过程是一个复杂的、动态的、数据量大的系统工程.如何建立简单完整的产品研制模型一直是业务过程优化(BPI,Business Process Improvement)中的难题.通过借鉴波音公司关于飞机构型管理和产品结构模块化的相关思想,强调构型管理技术在飞机研制的全生命周期过程中的重要性,明确构型项(CI,Configuration Item)准确的数学定义.依据构型管理简化产品的信息模型和Petri网(PN,Petri Net)描述、优化产品过程模型的特点,将Petri网理论与构型项结合起来保证全生命周期过程中飞机研制模型的一致性和完整性.提出CI-PN模型来描述整个飞机研制的信息和过程模型,并给出对翼盒研制过程模型描述、分析和优化的实例.
